DESCRIPTION

memcached(1) servers have the ability to increment and decrement keys
(overflow and underflow are not detected). This gives you the ability to use
memcached to generate shared sequences of values.

memcached_increment() takes a key and keylength and increments the value by
the offset passed to it. The value is then returned via the unsigned int
value pointer you pass to it.

memcached_decrement() takes a key and keylength and decrements the value by
the offset passed to it. The value is then returned via the unsigned int
value pointer you pass to it.

memcached_increment_with_initial() takes a key and keylength and increments
the value by the offset passed to it. If the object specified by key does
not exist, one of two things may happen: If the expiration value is
MEMCACHED_EXPIRATION_NOT_ADD, the operation will fail. For all other
expiration values, the operation will succeed by seeding the value for that
key with a initial value to expire with the provided expiration time. The
flags will be set to zero.The value is then returned via the unsigned int
value pointer you pass to it.

memcached_decrement_with_initial() takes a key and keylength and decrements
the value by the offset passed to it. If the object specified by key does
not exist, one of two things may happen: If the expiration value is
MEMCACHED_EXPIRATION_NOT_ADD, the operation will fail. For all other
expiration values, the operation will succeed by seeding the value for that
key with a initial value to expire with the provided expiration time. The
flags will be set to zero.The value is then returned via the unsigned int
value pointer you pass to it.

memcached_increment_by_key(), memcached_decrement_by_key(),
memcached_increment_with_initial_by_key(), and
memcached_decrement_with_initial_by_key() are master key equivalents of the
above.

RETURN

A value of type "memcached_return_t" is returned.
On success that value will be "MEMCACHED_SUCCESS".
Use memcached_strerror() to translate this value to a printable string.